I'm using SolidJS for Infumap (https://github.com/infumap/infumap), which is getting pretty big.

Two main comments that come to mind:

Because the state -> DOM mapping is non-trivial for my application, I ended up writing my own virtual DOM diffing code, a primary facet of React. I appreciate the ease of being able to circumvent this where it's not necessary and performance considerations dominate, though I admit i've not felt the need to do it anywhere yet.

The AI training data set for React is much larger. The models seem to do fine with SolidJS, though I suspect there is meaningful benefit to using React from this point of view.

Overall, I'm happy with where I'm at and I prefer the SolidJS way of thinking, though if I were to do it all over again, I'd probably just go with React for the above two reasons.